Prior art power supplies have limitations under conditions of changing loads or changing output voltage, particularly if the load is decreased at the same time that the output voltage is changed to a lower voltage as by an external programming command. Under conditions where the load decreases significantly or goes to zero, and the voltage is commanded to go to a lower value or zero, a prior art power supply would very likely have a spike upward in output voltage followed by a slow decrease to a final value, because of the time needed to discharge stored energy in the output filter inductor and capacitor.